Table 3.

Unadjusted and Adjusted Prevalence Ratios (PR)^a for Selected Menstrual Cycle Factors and modified Ferriman-Gallwey score ≥8 vs <8

	No. of women		Unadjusted		Adjusted
		PR	95% CI	PR	95% CI
Age at menarche, years
<12	1,585	1.29	1.15, 1.44	1.14	1.02, 1.27
12-13	2,826	1.00	Ref	1.00	Ref
14	630	0.89	0.74, 1.07	0.98	0.82, 1.17
≥15	501	1.03	0.86, 1.24	1.06	0.89, 1.27
Time to menstrual regularity, years	3,766	1.05	1.02, 1.08	1.04	1.01, 1.07
Cycle regularity
Regular	3,977	1.00	Ref	1.00	Ref
Irregular	1,565	2.01	1.82, 2.21	1.73	1.56, 1.91
Number of cycles (periods/year)	5,542	0.92	0.90, 0.93	0.94	0.93, 0.95
Cycle length, daysb	3,977	1.02	1.00, 1.05	1.02	1.00, 1.04
Cycle length, daysb
<28	1,087	1.00	Ref	1.00	Ref
28-35	2,816	1.17	0.99, 1.38	1.18	1.00, 1.39
≥36	74	1.73	1.14, 2.62	1.60	1.06, 2.42
Bleed length, days
<3	212	1.00	Ref	1.00	Ref
3-4	2,560	1.18	0.87, 1.61	1.09	0.81, 1.48
5-6	2,265	1.28	0.94, 1.75	1.18	0.87, 1.60
≥7	505	2.05	1.48, 2.83	1.59	1.16, 2.19
Bleed heaviness
Light	978	0.89	0.77, 1.04	0.94	0.81, 1.09
Moderate	2,889	1.00	Ref	1.00	Ref
Moderate/heavy	1,363	1.28	1.14, 1.44	1.18	1.05, 1.32
Heavy	312	1.74	1.47, 2.06	1.42	1.21, 1.67

^a=adjusted for cycle at study entry, smoking status (current vs not current), MET hours of physical activity per week (<10, 10-19, 20-39, ≥40), age (<25, 25-29, 30-34, ≥35 years), BMI (<18, 18-24, 25-29, 30-34, ≥35 kg/m²), caffeine (<100, 100-199, 200-299, >300 mg/day), last form of birth control being hormonal (yes vs no), alcohol intake per week (0, 1-6, 7-13, ≥14 drinks/week)

^b=among those with regular cycles (3,977)